What's a square edge?

JD

Was reading a site that talked about distinguishing business from proof strikes and they used the term 'square edge' when describing the rim of a proof coin. Exactly what is a square edge?

Conder101

When you hold up a proof coin and look at the edge where it meets the rims it will look like ] while on a typical business strike will have the corners clipped off or in cases of bad strikes the edge will be closer to )

JD

Thanks.